Electric drive device for a vehicle

Abstract

Electric drive device (1) for a vehicle (100), comprising: - an electrical machine (14) with a stator (15a) and a rotor (15b); - a main shaft arrangement (5) which is non-rotatably mounted on the rotor (15b) and extends along a main axis (6); - a connecting shaft (7) extending along a connecting axis (8); - a first housing part (2) with a casing region (9) in which the electrical machine (14) is housed, a first extended region (10) which extends radially to the main axis (6) away from the casing region (9) on a first axial side (12) of the casing region (9), a second extended region (11) which extends radially to the main axis (6) away from the casing region (9) on a second axial side (13) of the casing region (9), a first axial opening (23) which forms an edge (24) of the casing region (9) and of the first extended region (10) on the first axial side (12), and a second axial opening (25) which forms an edge (26) of the casing region (9) and of the second extended region (11) on the second axial side (13); - a second housing part (3) forming a drive-end bearing shield for the main shaft assembly (5) and covering the first axial opening (23); and - a third housing part (4) which forms a non-drive end bearing shield for the main shaft arrangement (5) and covers the second axial opening (25).

Description

The present invention relates to an electric drive device for a vehicle.EP 3 530 987 A1 discloses an integrated drive system for a vehicle comprising an electric machine and a transmission. The electric machine and the transmission are arranged in a multi-part housing. Further, the assembly includes a shaft mounted to a rotor of the electric machine and a side shaft coupled to the transmission.Electric drive devices for a vehicle having a main shaft assembly and a connecting shaft coupled to the main shaft assembly through a transmission may be disposed in a housing formed by a plurality of housing parts. Typically, the connecting shaft extends parallel to the main shaft and partly outside the housing to allow access to the connecting shaft.An object of the present invention is to provide an electric drive device having a main shaft assembly and a connecting shaft coupled to the main shaft assembly through the transmission with improved mechanical stability.The above object is achieved by an electric drive device for a vehicle, the electric drive device comprising: an electric machine having a stator and a rotor; a main shaft arrangement which is fixed to the rotor in a rotationally fixed manner and extends along a main axis; a connecting shaft which extends along a connecting axis; a first housing part having a shell portion in which the electric machine is accommodated, a first extended portion extending radially toward the main axis away from the shell portion on a first axial side of the shell portion, a second extended portion extending radially toward the main axis away from the shell portion on a second axial side of the shell portion opposite to the first axial side, a first axial opening forming an edge of the shell portion and the first extended portion on the first axial side, and a second axial opening forming an edge of the shell portion and the second extended portion on the second axial side; a second housing part forming a driving end shield for the main shaft assembly and covering the first axial opening; a third housing part forming a non-driving end shield for the main shaft assembly and covering the second axial opening; and a transmission configured to transmit rotational motion of the main shaft assembly to the connecting shaft and housed in the shell portion, the first extended portion, and the second housing portion; wherein the first extended portion and the second extended portion each include a connecting shaft hole through which the connecting shaft extends; wherein the first housing portion further includes a stiffening portion that extends axially to the connecting axis from the first extended portion to the second extended portion and that radially protrudes beyond the connecting shaft.The electric drive device for a vehicle includes an electric machine, a main shaft assembly, a connecting shaft, a first case, a second case, a third case, and a transmission.The electric machine has a stator and a rotor. The main shaft arrangement is attached to the rotor in a rotationally fixed manner. The main shaft extends along a main axis. The connecting shaft extends along a connecting axis.The first housing part has a jacket region, a first extended region, a second extended region, a first axial opening and a second axial opening. The electric machine is accommodated in the jacket region. The first extended portion extends radially to the major axis away from the skirt portion on a first axial side of the skirt portion. The second extended portion extends radially to the major axis away from the skirt portion on a second axial side of the skirt portion. The second axial side is opposite to the first axial side. The first axial opening forms an edge of the shell portion and the first extended portion on the first axial side. The second axial opening forms an edge of the skirt portion and the second extended portion on the second axial side.The second housing part forms a drive-end bearing shield for the main shaft arrangement and covers the first axial opening. The third housing part forms a non-drive end shield for the main shaft assembly and covers the second axial opening. The transmission is configured to transmit rotational movement of the main shaft assembly to the interconnecting shaft. The transmission is accommodated in the shell portion, the first extended portion, and the second housing part.The first extended portion and the second extended portion each include a connecting shaft opening. The connecting shaft extends through the connecting shaft openings. The first housing part further comprises a stiffening region. The stiffening region extends axially to the connection axis from the first extended region to the second extended region. The stiffening region protrudes radially beyond the connecting shaft.The invention is based on the consideration that the extended portions themselves form a mechanical weakening of the first housing part when the second and third housing parts are attached thereto to cover the axial openings. Advantageously, by providing the stiffening region between the extended regions, the stiffness of the entire housing structure of the electric drive device is partially increased. In this case, more robust operation of the electric drive device is possible.The main shaft assembly may be implemented by a single shaft or multiple shafts connected together. Preferably, the main axis and the connecting axis extend parallel.The third housing portion may also include a connecting shaft opening through which the connecting shaft may extend.Preferably, the second and third housing parts are fixed to the first housing part, for example, by screws extending into the first housing part. The housing parts are preferably made of metal. The casing region can have a substantially hollow cylindrical receiving space for the stator and the rotor.Preferably, the stiffening portion includes a first receiving portion extending from a position between the shell portion and the connecting shaft on a side of a plane lying on the connecting axis. Further, the stiffening portion may comprise a second receiving portion extending from a position between the shell portion and the connecting shaft on the other side of the plane.Advantageously, the stiffening region comprises a connecting part region which extends away from the casing region radially with respect to the main axis. In this case, the first receiving part region and the second receiving part region can extend away from the connecting part region at the position between the connecting shaft and the casing region.In a preferred construction, the receiving part portions and the first and second extended portions enclose a receiving space in which the connecting shaft is partially accommodated. The first and second elongated regions may further define a service opening for access to the receiving space. The service opening allows better serviceability of the connecting shaft.More specifically, the first receiving part region and / or the second receiving part region can have the shape of a hollow cylinder sector which partially surrounds the connecting shaft.Preferably, the first housing part is provided with a plurality of fastening openings configured for fastening the electric drive device to a support structure of the vehicle, wherein the fastening openings are arranged around the stiffening region. In particular, the fastening openings can be arranged around the service opening.Further, the first housing portion may be provided with process attachment openings configured to attach the electric drive device to a test stand, the process attachment openings being disposed around the stiffening region. In particular, the process fastening openings can be arranged around the service opening. Furthermore, the process fastening openings can be provided on the jacket region of the first housing part.In the electric drive device according to the invention, the stiffening portion may include drain holes. The drain holes prevent condensed water from accumulating on a side of the first case. More specifically, the first receiving part portion may be provided with the drain holes. Additionally or alternatively, the connecting portion may be provided with the drain holes.In a preferred embodiment of the electric drive device according to the invention, the transmission is configured to receive a drive shaft extending along the connection axis and to transmit the rotational movement of the main shaft arrangement to the drive shaft. Further, the first housing portion may include a drive shaft aperture through which the connecting axle extends. The transmission may include a differential coupling the connecting shaft and the drive shaft. The differential may be further configured to support the connecting shaft and the drive shaft in the housing parts. Typically, the differential is accommodated in the first extended portion and the second case.Further, the electric drive device may include the drive shaft received by the transmission. The drive shaft may extend through the drive shaft opening of the second housing part.The electric drive device may further include a bearing disposed in the third housing part and configured to support the main shaft assembly and / or a bearing disposed in the second housing part and configured to support the main shaft assembly. Another bearing configured to support the main shaft assembly may be disposed in the shell portion.The electric drive device may further include a bearing disposed in the third housing part and configured to support the connection shaft. The connecting shaft may be further supported by the transmission, e.g., the aforementioned differential.Preferably, the electric drive device according to the invention further includes an inverter device mounted on the third case on a side opposite to the first case. Further, the inverter device may include a housing structure formed with a cutout such that the cutout partially surrounds the connection axis to allow access to the connection shaft.The invention may further relate to an electric vehicle comprising an electric drive device according to the invention. The electric drive device may be configured to propel the vehicle.The electric drive device may form an electric axle of the vehicle.The vehicle may be a battery-powered electric vehicle (BEV) or a fuel cell powered vehicle. The vehicle may further be a hybrid vehicle additionally including an internal combustion engine.Further details and advantages of the invention are disclosed below, with reference to the drawings. The drawings show schematically: FIG. 1 is a perspective view of an embodiment of the electric driving device according to the invention; FIG. 2 is a schematic diagram of other components disposed in the housing portions; FIGS. 3 and 4 each show a perspective view of the first housing part of the electric drive device; FIG. 5 is a top view of the first housing part; and FIG. 6 is a schematic diagram of an embodiment of the vehicle according to the invention.FIG. 1 is a perspective view of an embodiment of an electric drive device 1.The electric drive device 1 comprises a first housing part 2, a second housing part 3, a third housing part 4 and a main shaft arrangement 5, which is concealed in FIG. 1. The main shaft arrangement 5 (see FIG. 2 ) which extends along a main axis 6 is accommodated in the housing parts 2, 3, 4. Furthermore, the electric drive device comprises a connecting shaft 7, which can be seen in part in FIG. 1 and extends along a connecting axis 8. In the present embodiment, the axes 6, 8 extend in parallel.The first housing part 2 comprises a jacket region 9, a first extended region 10 and a second extended region 11. In this case, the first extended region 10 extends away on a first axial side 12 of the jacket region 9 and the second extended region 11 extends away on a second axial side 13 of the jacket region 9.FIG. 2 is a schematic diagram of other components disposed in the housing parts 2, 3, 4.The electric drive device 1 further comprises an electric machine 14 having a stator 15 aand a rotor 15 b. The electric machine may be a permanent-excited or electrically excited synchronous machine or an induction motor. The main shaft arrangement 5 is attached to the rotor 15 bin a rotationally fixed manner.The electric machine 14 is accommodated in the casing region 9. Furthermore, the electric drive device 1 comprises a transmission 16 configured to transmit a rotational movement of the main shaft arrangement 5 to the connecting shaft 7. The gear 16 is accommodated in the casing portion 9, the first extended portion 10, and the second case 3.Furthermore, the second housing part 3 forms a drive-end bearing plate for the main shaft arrangement 5. The third housing part 4 forms a non-drive-end bearing plate for the main shaft arrangement 6, and a second bearing 18 which supports the main shaft arrangement 5 is arranged in the third housing part 4. A third bearing 19 supporting the main shaft assembly 6 is disposed in the shell portion 9.As further seen in FIG. 2, a bearing 20 supporting the connecting shaft 7 is disposed in the third housing part 4. In this case, the connecting shaft 7 is further supported by the transmission 16, in particular by a differential 21 of the transmission 16.The transmission 16 is further configured to receive a drive shaft 22, which is an optional component of the electric drive device 1. The input shaft 22 extends along the connection axis 8, and the transmission 16 is configured to transmit the rotational movement of the main shaft assembly 5 to the input shaft 22. The drive shaft 22 may be accommodated in the differential 21. Access to the drive shaft 22 is possible via a drive shaft opening (concealed in FIG. 1 ) in the second housing part 3.FIGS. 3 to 5 each show the first housing part 2, wherein FIG. 3 is a perspective view from the first axial side 12, FIG. 3 is a perspective view from the second axial side 13, and FIG. 5 is a plan view.The first housing part 2 has a first axial opening 23, which forms an edge 24 of the jacket region 9 and of the first extended region 10 on the first axial side 12. The second axial opening 25 of the jacket portion 9 forms an edge 26 and the second extended portion 11 on the second axial side 13. As can be seen in connection with FIG. 1, the second housing part 3 covers the first axial opening 23 and the third housing part 4 covers the second axial opening 25.Further, the first extended portion 10 comprises a connecting shaft opening 27 and the second extended portion 11 comprises a connecting shaft opening 28. The connecting shaft 7 extends through the connecting shaft openings 27, 28, 29.As can be further seen in FIGS. 1, 3 and 4, the first housing part 2 comprises a stiffening region 30, which extends axially to the connection axis 8 from the first extended region 10 to the second extended region 12 and which projects radially beyond the connection shaft 7.More specifically, the stiffening portion 30 includes a first receiving portion portion 31 and a second receiving portion 32. the receiving portion portions 31, 32 extend from a position between the shell portion 9 and the connecting shaft 7 on opposite sides of a plane lying on the connecting axis 8. The receiving part regions 31, 32 have the shape of a hollow cylinder sector, which it partially surrounds the connecting shaft 7. The receiving part portions 31, 32 and the first and second extended portions 10, 11 enclose a receiving space 34 in which the connecting shaft 7 is partially accommodated, and define a maintenance opening 35 for access to the receiving space 34.As best seen in FIG. 5, the stiffening region 30 further comprises a connecting portion 33 which extends radially to the main axis 6 away from the skirt region 9. The first receiving part portion 31 and the second receiving part portion 32 extend away from the connecting part portion 33 at the position between the connecting shaft 7 and the shell portion 9.Moreover, the first housing part 9 is provided with a plurality of fastening openings 36 configured to fasten the electric drive device 1 to a support structure of a vehicle 100 (see FIG. 6 ), the fastening openings 36 being arranged around the maintenance opening 35.Further, the first case 9 is provided with process fixing holes 37 configured to fix the electric drive device 1 to a test stand (not shown). The process mounting holes 37 are arranged around the service hole 35. Further process fastening openings 38 arranged at other positions of the first housing part 9 are shown in FIGS. 1, 3, 4 and 5.Further, the stiffening portion 30 includes drain holes 39, 40. the first receiving portion 31 is provided with the drain holes 39, and the connecting portion 33 is provided with the drain holes 40, for example.Referring back to FIG. 1, the electric drive device 1 further includes an inverter device 41 mounted on the third housing part 4 on a side opposite to the first housing part 2. The inverter device 41 includes a housing structure 42 formed with a cutout 43 such that the cutout 43 partially surrounds the connection shaft 8 to allow access to the connection shaft 7.FIG. 6 is a schematic diagram of a vehicle 100 including the electric drive device 1 according to the above-described embodiment. The vehicle 100 is a battery powered vehicle (BEV). Alternatively, the vehicle 100 further includes an internal combustion engine (not shown) and is a hybrid vehicle.References included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedEP 3 530 987 A1

[0002]

Claims

An electric drive device (1) for a vehicle (100), the electric drive device (1) comprising: - an electric machine (14) having a stator (15a) and a rotor (15b); - a main shaft arrangement (5) which is attached to the rotor (15b) in a rotationally fixed manner and extends along a main axis (6); - a connecting shaft (7) which extends along a connecting axis (8); - a first housing part (2) having (i) a casing region (9) in which the electric machine (14) is accommodated, (ii) a first extended region (10) which extends radially to the main axis (6) away from the casing region (9) on a first axial side (12) of the casing region (9), (iii) a second extended region (11), which extends radially with respect to the main axis (6) away from the casing region (9) on a second axial side (13) of the casing region (9), which is opposite the first axial side (12), (iv) a first axial opening (23) which forms an edge (24) of the casing region (9) and of the first extended region (10) on the first axial side (12), and (v) a second axial opening (25) which forms an edge (26) of the casing region (9) and of the second extended region (11) on the second axial side (13); - a second housing part (3) which forms a drive-end-side bearing shield for the main shaft arrangement (5) and covers the first axial opening (23); - a third housing part (4) which forms a non-drive-end-side bearing shield for the main shaft arrangement (5) and covers the second axial opening (25); and - a transmission (16) configured to transmit a rotational movement of the main shaft arrangement (5) to the connecting shaft (7) and accommodated in the shell region (9), the first extended region (10) and in the second housing part (4); wherein the first extended region (10) and the second extended region (11) each comprise a connecting shaft opening (27, 28) through which the connecting shaft (7) extends; wherein the first housing part (2) further comprises a stiffening region (30) which extends axially to the connecting axis (9) from the first extended region (10) to the second extended region (11) and which radially protrudes beyond the connecting shaft (7).The electric drive device according to claim 1, wherein the stiffening portion (30) comprises a first receiving portion portion (31) extending from a position between the shell portion (9) and the connecting shaft (7) on a side of a plane lying on the connecting shaft (8).The electric drive device according to claim 2, wherein the stiffening portion (30) comprises a second receiving portion portion (32) extending from a position between the shell portion (9) and the connecting shaft (7) on the other side of the plane.The electric drive device according to claim 3, wherein the stiffening region (30) comprises a connecting part region (33) which extends radially to the main axis (6) away from the casing region (9), wherein the first receiving part region (31) and the second receiving part region (32) extend away from the connecting part region (33) at the position between the connecting shaft (7) and the casing region (9).The electric drive device according to claim 3 or 4, wherein the receiving part portions (31, 32) and the first and second extended portions (10, 11) enclose a receiving space (34) in which the connecting shaft (7) is partially accommodated, and define a maintenance opening (35) for access to the receiving space (34).Electric drive device according to one of Claims 2 to 5, wherein the first receiving part region (31) and / or the second receiving part region (32) have the shape of a hollow cylindrical sector which partially surrounds the connecting shaft (7).The electric drive device according to any of the preceding claims, wherein the first housing part (2) is provided with a plurality of fastening openings (36) configured for fastening the electric drive device (1) to a support structure of the vehicle (100), wherein the fastening openings (36) are arranged around the stiffening region (30).The electric drive device according to any of the preceding claims, wherein the first housing part (2) is provided with process attachment openings (37) configured for attaching the electric drive device (1) to a test stand, wherein the process attachment openings (37) are arranged around the stiffening region (30).The electric drive device according to any of the preceding claims, wherein the stiffening region (30) comprises drain holes (39, 40).The electric drive device according to claim 9 as dependent on claim 2, wherein the first receiving part portion (31) is provided with the drain holes (39).The electric drive device according to claim 9 or 10 as dependent on claim 4, wherein the connection portion (33) is provided with the drain holes (40).The electric drive device according to any of the preceding claims, wherein the transmission (16) is configured to receive a drive shaft (22) extending along the connection axis (8) and to transmit the rotational movement of the main shaft arrangement (5) to the drive shaft (22).The electric drive device of claim 12, further comprising the drive shaft (22) received by the transmission (16).The electric drive device according to any of the preceding claims, further comprising: - a bearing (17) arranged in the second housing part (3) and configured to support the main shaft assembly (5), and / or - a bearing (18) arranged in the third housing part (4) and configured to support the main shaft assembly (5), and / or - a bearing (20) arranged in the third housing part (4) and configured to support the main shaft assembly (7).The electric drive device according to any one of the preceding claims, further comprising: an inverter device (41) mounted on the third housing part (4) on a side opposite to the first housing part (2), the inverter device (41) comprising a housing structure (42) formed with a cutout (43) such that the cutout (43) partially surrounds the connection shaft (8) to allow access to the connection shaft (7).

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